Colin Kaepernick has averaged fewer than 4.2 yards per pass attempt in each of his past two starts, losses to Carolina (10-9) and New Orleans (23-20). Kaepernick averaged 4.14 yards per attempt against the Panthers and 4.10 yards per attempt against the Saints. In 2013, nine quarterbacks have averaged fewer than 4.2 yards per pass with at least 22 attempts in a game. Kaepernick is the only quarterback to do so twice: …

Adam Snyder, a nine-year veteran with 131 career starts, replaced Iupati on Sunday and swill presumably start in his spot when the 49ers visit Washington on Monday night. Washington (3-7) ranks 28th in total defense (389.9 yards per game) and 30th in points allowed (31.1). …

The signing of Swanson was not influenced by the rib injury cornerback Tarell Brown sustained in a 23-20 loss to the Saints on Sunday. Last week, Swanson was accepting congratulations for signing with the 49ers on his Twitter account. …

Iuapti was injured late in the third quarter when running back Frank Gore crashed into the back of his left leg after he was tackled for no gain by nose tackle Brodrick Buckley. Iuapti was replaced by Adam Snyder, 31, a nine-year veteran with 131 career starts. …